Most doctors in developed nations have never seen a diphtheria case. It's a wonderful thing that we've come so far. Sadly, diphtheria still regularly occurs in the Third World.

Diphtheria is an extremely contagious and often life-threatening infection that usually attacks the membranes of the throat and nose. Although usually confined to the upper respiratory tract, in the most serious cases it attacks the nervous system and the heart.

It is characterized by the formation of a tough membrane attached firmly to the underlying tissue that will bleed if forcibly removed. This is how diphtheria got its name as diphtheria is the Greek word for leather.

The infection begins in one tonsil and spreads to the other, the uvula, the soft palate, the pharyngeal wall, the larynx, the trachea, and the bronchial tree. Bronchial obstruction occurs and death is due to suffocation.

Diphtheria is very easily spread by an infected person coughing, sneezing, or breathing on a person. Early symptoms are a sore throat, a fever, and chills. Swallowing is difficult. But sometimes there are no symptoms for a considerable time. Yet during this time the infected person can spread the disease to others.

Diphtheria is caused by Corynebacterium diphtheriae. If left untreated, this bacterium produces a powerful toxin that is carried in the bloodstream throughout the body. It can cause paralysis and heart failure.

Diphtheria was once a greatly feared disease and far more widespread. In the US in the 1920s, it struck about 150,000 people per year. About 10 per cent died. Babies and children were particularly vulnerable.

According to the US Centres for Disease Control and Prevention in Atlanta, there were 918 diphtheria cases in 1960, 435 in 1970, 98 in 1980, 91 in 1990, and 88 in 2000.

Diphtheria is the "D" in the DTP triple vaccine.

An account exists of the last major diphtheria epidemic in Sydney, Australia that took place in 1937. The disease advanced up the side of one street and down the other side killing nearly every child under age five.

Stephen Juan, Ph.D. is an anthropologist at the University of Sydney. Email your Odd Body questions to [email protected]